I suppose, this is science, well, in a way - Monkeys use sex toys to masturbate

[abaris]

In a research paper published on Aug. 4 in the journal Ethology: International Journal of Behavioural Biology, researchers analyzed how this population of Balinese monkeys play with stones. Among more innocuous uses, including biting and gathering the stones, video footage collected between 2016 to 2019 also shows hundreds of instances of monkeys in the sanctuary, both male and female, tapping and rubbing the stones on their genitals—seemingly in a state of sexual arousal.

https://www.vice.com/en/article/g5vyk9/m...e-sex-toys

May I just add, which originally caught my attention in a German article: They're called long-tailed macaques. Now, tail, in German, can have several meanings, such as the male genital. Which gave the story a whole new meaning.